The problem of the origins of life is one of the great questions of science, if not the greatest question that science can study. Origins of life research takes many different forms according to the theory of origins of life being tested. This is such a diversity of theories of the origins of life that they cannot all be true, but the field remains so little constrained that alternative theories are mostly empirically equivalent at this time, and much work remains to be done to further constrain the conditions of the origins of life.

Scientific theories about the origins of life can be traced back to Darwin’s speculation of “some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity… that a protein compound was chemically formed, ready to undergo still more complex changes.” It was not until Alexander Oparin’s Vozniknovenie zhizni na zemle, originally published in 1936, and translated into English as The Origin of Life in 1938, that origins of life research was put on a truly scientific footing. It is from Oparin that we get the idea that life initially appeared in Earth’s oceans, an Oparin ocean.

Another important milestone in origins of life research was the Miller-Urey experiments in 1952, which successfully synthesized simple organic molecules from chemicals believed to be present in the primordial atmosphere of Earth. Today origins of life researchers investigate seafloor hydrothermal vents (“black smokers”) and hot springs as possible environments for the origins of life. Even nuclear geysers have been proposed as a possible environment for the emergence of life.

Part of the difficulty in origins of life research is that the evidence for the origins of life on Earth has all been erased by subsequent geological and biological processes, and one way to address this lack of evidence is to look for origins of life on other worlds where the process is not billions of years in the past. Thus origins of life research is deeply integrated with astrobiological problems. The problem of the origins of life on Earth requires that we think of Earth as a planet among planets in the universe, and we think of other planets as being possible analogues of Earth.  

Origins of life research also overlaps with the study of extremophiles, as the three domain system, which distinguishes archaea, bacteria, and eukarya as the fundamental divisions in terrestrial life, finds mostly extremophiles—and, specifically, mostly methanogens—at the root of the tree of  life.